There have been developed spectroscopy microscopes which visualize two-dimensional distribution of structures included in tissue, such as cell nuclei, cytoplasm, fiber, and so forth, by spectroscopy such as Raman scattering spectroscopy. Spectroscopy microscopes yield spectral information owing to molecules included in the structures, in addition to morphology information of the structures. This information enables tissue to be distinguished free of dyes. However, two-dimensional distribution only includes information of a particular cross-section, so the morphology information of the structure may be insufficient for distinguishing the structure at a higher level of accuracy. As an attempt to solve this, three-dimensional spectroscopic measurement aims to obtain three-dimensional distribution of spectral information. Such three-dimensional spectroscopic measurement may be performed by first obtaining two-dimensional distributions for a great number of adjacent tissue sections, and then re-constructing these, or by obtaining multiple Z-stack images (different images at multiple Z-positions) of a specimen, for example. Three-dimensional distribution images have three-dimensional form information unattainable by two-dimensional distribution, so structures can be distinguished at a high level of accuracy.
When analyzing three-dimensional distribution images of spectral information, a spectroscopic microscope user specifies a feature region in a three-dimensional distribution image, and distinguishes structures based on three-dimensional form and spectral information (wavelength, signal intensity, spectrum, etc.) of that feature region.
Technology to assist specifying of feature regions in three-dimensional distribution images of spectral information has been disclosed PTL 1 discloses a system which specifies and displays a three-dimensional region of a light emission source as a feature region. According to PTL 1, three-dimensional position information of a light emission source existing within the specimen is automatically calculated using spectroscopic spectrums, which facilitates specifying a light emission source. PTL 2 discloses a system where a spectroscopic spectrum of a reference sample is referenced, and a region of the specimen having a spectroscopic spectrum similar e reference sample is displayed as a feature region.